Sealing device



Dec. 21 1926.

ZjX eU 0 Patented Een. 2l, i923@ SNOWDEN B. REDFIELD, GF EASTON, PEE-ISYLVANIA, ASSGNOP, TG INGERSOLL-RAND COMPANY, Oli' JERSEY CITY, NEW* JERSEY, A. CORPORATN 0F NEW JERSEY.

ESEALIIG DEVCE.

Application filed uly l5,

This invention relates to compressors and the like, but more particularly to a sealing` device for the inlet and exhaust valves oit compressors, especially those handling; noi;- ious )in compressors in which inlet and exhaust valves of the plate type are used tor controlling the admission and exhaust oit' fluid into and from the cylinde, some dilliculty is at times experienced in maintaining fluid tight `joints between the parts which comprise the valve securing means. Such means usually consist ot a suitable cover for the opening in the outer wall through which the valve is inserted into the head, and a set screw is then screwed into the cover to bear against the valve tor clamping,` the valve to its seat.

@wing 'to the clearance which usually ex:- ists between the. screw and the tap hole some ot the fluid being compressed escapes therethrough to the atmosphere. A well known method intended to prevent such leakage consists in placing an ordinary cap nut over the outer end ot the set screw. rl`he undesirable feature of this construction is that the head of the screw must ot necessity be of smaller cross sectional area than the body ot the screw. As a result, only small flats may be iormed on the head, thus providing only a small hold for a wrench and in consequence the corners ot the head quickly become worn and rounded.

The present invention is intended to overcome these limitations and a iew of its objects are to prevent leakage of fluid along the threads of the set screw and associated parts and to permit the formation ot a large head on the set screw.

Other objects will be in part obvious and in part pointed out hereinafter.

The invention consists of the combination ot elements and features ot construction substantially as hereinafter described and more particularly pointed out in the appended claims and illustrated in the accompanying drawings, in w rich- Figure l is a sectional elevation of a portion of a compressor head showing a set screw and the cap nut constructed in accoi'oance with the practice ot the invention, and

Figure 2 is an outsi le view in elevation ot the cap nut.

Referring to the drawings in which is ilieee. serial No. marie.

lustrated practical application ot the in- `if'ention, A designates a portion ot a compressor head or cylinder havingan inner wall B and an outer wall C. A valve seat opening D is formed in the inner wall B and its outer end is provided with counterbored portion E to receive a linings F ot a plate valve seat G which in this instance extends into the valve seat opening l). A valve plate ll is seated on the valve seat and a stop plate J spaced a slight distance trom the plate valve l-l servos to limit the liit ot the valve plate.

rllhe parts comprising the valve assembly are intended to be clamped together in the usual manner, that is, by a stud bolt (not shown) on which is screwed a nut l to' seat on the valve stop J and the nut K is locked against accidental removal by a jam nut L.

ln the outer wall C is formed an opening preferably coaxial with the valve seat opening` l) and of suiliciently larger diamalve seat opening to permit eter than said the plate valve assembly to be readily nsei-ted therethrough. The outer end ot the opening O is counterbored to term a shoulder P upon which is seated a cover plate Q. A gasket lt may be interposed between the cover plate Q and the shoulder l? to form a fluid tight joint therebetween.

Any suitable means may be provided tor clamping the cover plate tightly on the head A. ln this instance, tap bolts S are screwed into the wall C and bear with their heads on a flange T ol the cover plate ln accordance with the present invention, a threaded aperture U is formed in the cover plate Q preferably coaxial with the valve assembly to receive a set screw if having' a plain forward extension W adapted to seat on the jam nut L. intermediate the threaded portion ot the screw V is :termed a head X of considerably larger cross sectional area than the screw V thus forming; large flats Y for the reception or' a wrench whereby the screw V may be manipulated.

ln order to prevent the escape ot any fluid which may leak through the threaded aperture U to the atmosphere, a cap nut Z is screwed on the outer end o ot the screw V and has a slrirtc, the trontend ol which may be clamped firmly against the cover plate Q; or, it desired, a gasket al may be interposed between the cover plate and the frontend of the skirt c. In this instance lli the cover plate Q, is provided with a recess e tor the reception ot the gasket CZ and also to cooperate with a cylindrical portion f formed on the front end of the cap nut .Z for the purpose ot centralizing said cap nut and locating the gasket. Formed forwardly ot the threaded portion g of the cap nut Z is a recess It, This recess is preferably ot sutiieient depth and cross sectional area to permit the entrance ot the head X thereinto without. contacting with the cap nut.

By means ot the construction hereinloetore described a perfect seal may he maintained between the cap nut and the cover plate ln this way any tluid which may leak through the threaded aperture U will loe prevented 'from iinding its way to the atmosphere, This is especiallq.7 desirable in compressing` fluids such as' ammonia Iand other `gases, which, when inhaled 'frequentlyv cause great discomtort to the attendant or injury to the health.

Another desirable feature ol this invention is that this construction permits or a large head being formed on thc set screw, thus providing a large area oit contact tor a wrench and also preventing; the objectionable rounding ot the corners of the head X which has hereto-tore rendered such screws diiicult ot manipulation.

l claim:

l. ln a con'iprcssor or the like, the combination ot a coter having` a threaded aperture, a screw to cooperate with the aperture, a head intermediate the ends ot the screw, said head being ot greater cross sectional area. than the screw to obtain increased contact surface tor manipulation, and a cap nut on the screw, said cap nut having` a recess ot larger diameter than the head to receive said head.

2. r'n a compressor or the like, the combination ot a cover having' a threaded aperture, a screw to cooperate with the aperture, a head intermediate the ends ot the screw, said head being of greater cross sectional arca than the screw, a cap nut on the end ot the screw, a skirt on the cap nut to encircle the head, and a gasket between the skirt and the cover to prevent the escape of Huid leaking' through the threaded aperture.

in testimony whereotl have signed this speciiication.

, NUVVDEN B. REDFIELD. 

